Acceleration and support provided by VideoHWVIDC

The VideoHWVIDC module 0.48 provides hardware access for the native VIDC20 hardware used in RiscPC, A7000 and RiscStation hardware. The acceleration provided is described below. It covers the vast majority of common operations which are used by applications. The operations are broken down into the core components for the abstracted video system.

All features which are not supported by the hardware driver will be deferred to the software driver which will use direct screen access to provide the required operation, or update its internal state.

Glossary :
  • 'Not supported' - the hardware driver does not provide any facilities for this feature; it will be passed to the software driver.
  • ''Supported' - the hardware driver provides this facility but it does not gain from specialised hardware features for faster operation.
  • 'Accelerated' - the hardware driver provides this facility and uses specialised hardware features to avoid direct screen access.
Text (VDU4-style text output)
   VideoV_Text_ChangeDestination  : Not supported
   VideoV_Text_DefineChar         : Not supported
   VideoV_Text_SetTextColour      : Not supported
   VideoV_Text_WriteTextChar      : Not supported
   VideoV_Text_TextCursor         : Not supported
   VideoV_Text_ClearBox           : Not supported
   VDU graphics operations
   VideoV_Graf_SetColour1         : Not supported
   VideoV_Graf_SetColour2         : Not supported
   VideoV_Graf_ChangeDestination  : Not supported
   VideoV_Graf_ChangeBase         : Not supported
   VideoV_Graf_ReadPrimitives     : Not supported
   VideoV_Graf_Rectangle          : Not supported
   VideoV_Graf_Triangle           : Not supported
   VideoV_Graf_Parallelogram      : Not supported
   VideoV_Graf_BlockCopy          : Not supported
   VideoV_Graf_CircleOutline      : Not supported
   VideoV_Graf_CircleFill         : Not supported
   VideoV_Graf_CircleArc          : Not supported
   VideoV_Graf_CircleSegment      : Not supported
   VideoV_Graf_CircleSector       : Not supported
   VideoV_Graf_EllipseOutline     : Not supported
   VideoV_Graf_EllipseFill        : Not supported
   VideoV_Graf_FillRight          : Not supported
   VideoV_Graf_FillLeftAndRight   : Not supported
   VideoV_Graf_FillFlood          : Not supported
   VideoV_Graf_PolyHLine          : Not supported
Graphics primitives
   HLine                          : Not supported
   VLine                          : Not supported
   Point                          : Not supported
Mouse pointer operations
   VideoV_Pointer_Define          : Supported
   VideoV_Pointer_Select          : Supported
   VideoV_Pointer_Update          : Supported
   VideoV_Pointer_Remove          : Supported
   VideoV_Pointer_SetPalette      : Supported
   Mode / screen operations
   VideoV_Mode_VetMode            : Supported
   VideoV_Mode_SetMode            : Supported
   VideoV_Mode_Scroll             : Accelerated through frame base scroll
   VideoV_Mode_SetPalette         : Supported
   VideoV_Mode_Enable             : Supported
   VideoV_Mode_Disable            : Supported
   VideoV_Mode_PowerSave          : Supported
   VideoV_Mode_SetRGBTable        : Supported
   VideoV_Mode_AccelConfigure     : Supported
   VideoV_Mode_AccelControl       : Supported
   VideoV_Mode_DisplaySelect      : Supported
   VideoV_Mode_BankCount          : Supported
   VideoV_Mode_BankDisplay        : Supported
   VideoV_Mode_BankDriver         : Supported
   VideoV_Mode_BankCopy           : Not supported
   VSync IRQ provision            : Supported
   Monitor EDID acquisition       : Not supported

This documentation is copyright 3QD Developments Ltd 2013 and may not be reproduced or published in any form without the copyright holders permission. RISC OS is subject to continuous development and improvement as such all information is reproduced by 3QD Developments Ltd in good faith and is believed to be correct at the time of publication E&OE. 3QD Developments Ltd cannot accept any liability for any loss or damage arising from the use of any information provided as part of the RISC OS Documentation.

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